CREATE TABLE sparse_pk (
    pcol1  INT NOT NULL,
    col2 VARCHAR(200),
    pcol3 INT NOT NULL,
    PRIMARY KEY (pcol1, pcol3)
);

using iAnywhere.MobiLink.Script;
using System;
using System.IO;
using System.Data;
using System.Text;
...

// The method used for the handle_UploadData event.
public void HandleUpload(UploadData ut) {

    // Get an UploadedTableData for the sparse_pk table.
    UploadedTableData sparse_pk_table = ut.GetUploadedTableByName("sparse_pk");

    // Get updates uploaded by the MobiLink client.
    using( UpdateDataReader data_reader = sparse_pk_table.GetInserts() ) {

        while (data_reader.Read()) {
            data_reader.SetNewRowValues();
            StringBuilder row_str = new StringBuilder("New values ( ");
            row_str.Append(data_reader.GetString(0)); // pcol1
            row_str.Append(", ");
            if (data_reader.IsDBNull(1)) {
                row_str.Append("<NULL>");
            }
            else {
                row_str.Append(data_reader.GetString(1)); // col2
            }
            row_str.Append(", ");
            row_str.Append(data_reader.GetString(2)); // pcol3
            row_str.Append(" )");
            data_reader.SetOldRowValues();
            row_str.Append(" Old Values (");
            row_str.Append(data_reader.GetString(0)); // pcol1
            row_str.Append(", ");
            if (data_reader.IsDBNull(1)) {
                row_str.Append("<NULL>");
            }
            else {
                row_str.Append(data_reader.GetString(1)); // col2
            }
            row_str.Append(", ");
            row_str.Append(data_reader.GetString(2)); // pcol3
            row_str.Append(" )");
            writer.WriteLine(row_str);
        }
    }
}